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Purification method for 2,3-dimethylpyridine

A lutidine and purification method technology, which is applied in the field of 2,3-lutidine purification, can solve the problems of complex operation and unsuitability for large-scale production, and achieve the effect of high purity and simple preparation method

Inactive Publication Date: 2012-03-21
ANHUI COSTAR BIOCHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, pyridine base is mainly produced by chemical synthesis. Chemical synthesis generally uses shape-selective molecular sieves as catalysts, and is formed by catalytic gas-phase condensation reaction between aldehydes and ammonia. Purification of pyridine is generally treated by sulfuric acid, potassium hydroxide, etc. and then rectified. Obtained, or the method of potassium permanganate oxidation, and then treated with sodium hydroxide and calcium oxide, but these methods can more or less purify pyridine, but the operation is complicated and not suitable for large-scale production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1: 2, the purification method of 3-lutidine, comprises the following steps:

[0016] (1) Salt formation: 2000kg of ethanol, 3000kg of 2,3 lutidine crude products and 1200kg of sulfuric acid were added to the salt formation kettle successively, and the temperature was raised to 170-180°C and refluxed. Filter after 65 minutes;

[0017] (2) The filtrate obtained in step (1) is injected into the reactor for recrystallization, kept at 4-6°C for 55-65 minutes, filtered, and the filtered solid was incorporated into the salt-forming kettle to form salt;

[0018] (3) Washing of salt-forming solids: the solid after salt-forming in step (2) is soaked and washed with ethanol for 2-3 times, soaking for 25-35 min each time, filter by pressure, and take a solid sample to detect the purity of 2 and 3-lutidine;

[0019] (4) Analysis: Add the solid obtained by pressure filtration in step (3) into the analysis kettle, add 1.8-2.2 times the weight of the solid to dissolve in wate...

Embodiment 2

[0021] Example 2 : the purification method of 2,3-lutidine, comprises the following steps:

[0022] (1) Salt formation: 2000kg of ethanol, 3000kg of 2,3 lutidine crude products and 1200kg of oxalic acid were added to the salt formation kettle successively, heated to 170-180°C and refluxed, kept for 30-40min and then cooled to normal temperature, stirred and crystallized for 55- Filter after 65 minutes;

[0023] (2) The filtrate obtained in step (1) is injected into the reactor for recrystallization, kept at 4-6°C for 55-65 minutes, filtered, and the filtered solid was incorporated into the salt-forming kettle to form salt;

[0024] (3) Washing of salt-forming solids: the solid after salt-forming in step (2) is soaked and washed with ethanol for 2-3 times, soaking for 25-35 min each time, filter by pressure, and take a solid sample to detect the purity of 2 and 3-lutidine;

[0025] (4) Analysis: Add the solid obtained by pressure filtration in step (3) into the analysis kett...

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PUM

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Abstract

The invention discloses a purification method for 2,3-dimethylpyridine. The refined product of 2,3-dimethylpyridine is obtained by adding ethanol and diacid into the crude product of 2,3-dimethylpyridine and sequentially subjecting an obtained mixture to salt forming, crystallization, rinsing, desorbing, extraction and solvent removal. The method provided in the invention is simple; effective purification of 2,3-dimethylpyridine can be carried out through a simple process, and obtained 2,3-dimethylpyridine has high purity.

Description

technical field [0001] The invention relates to a chemical purification method, in particular to a purification method of 2,3-lutidine. Background technique [0002] Pyridine is widely used in medicine, pesticide and other fields. In addition, they are also widely used in rubber industry, surfactant and dye industry, etc. Pyridine with a content of less than 99% is generally called crude pyridine and can be used as a solvent, Pyridine with a content higher than 99.5% is usually called pure pyridine and can be used in most chemical synthesis. [0003] At present, pyridine base is mainly produced by chemical synthesis. Chemical synthesis generally uses shape-selective molecular sieves as catalysts, and is formed by catalytic gas-phase condensation reaction between aldehydes and ammonia. Purification of pyridine is generally treated by sulfuric acid, potassium hydroxide, etc. and then rectified. Obtain, or first potassium permanganate oxidation, then use the method for sodium ...

Claims

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Application Information

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IPC IPC(8): C07D213/16C07D213/127
Inventor 韦永飞葛九敢王长才方红新
Owner ANHUI COSTAR BIOCHEM CO LTD